docs: def after(func):
      """
      Run a function after the handler is invoked, is passed the response
      and must return an response too.
  
      Usage::
  
          >>> # to create a reusable decorator
          >>> @after
          ... def gnu_terry_pratchett(retval):
          ...     retval.setdefault('Headers', {})['X-Clacks-Overhead'] = 'GNU Terry Pratchett'
          ...     return retval
          >>> @gnu_terry_pratchett
          ... def handler(event, context):
          ...     return {'body': ''}
          >>> handler({}, object())
          {'body': '', 'Headers': {'X-Clacks-Overhead': 'GNU Terry Pratchett'}}
      """
      class AfterDecorator(LambdaDecorator):
          def after(self, retval):
              return func(retval)
  
      return AfterDecorator